Paper Weight Converter
Convert between GSM, US bond weight, US cover weight, and UK paper weight standards.
Type in any field — the others update instantly.
Paper weight is measured differently in each region.
GSM (grams per square meter): The international standard. Used worldwide. Higher GSM = thicker, heavier paper.
US Bond Weight (lb): Based on 500 sheets of 17" × 22" paper.
- Conversion: GSM = Bond weight × 3.7597
US Cover Weight (lb): Based on 500 sheets of 20" × 26" paper.
- Conversion: GSM = Cover weight × 2.7080
Common paper weights:
| Paper Type | GSM | US Bond (lb) | US Cover (lb) |
|---|---|---|---|
| Thin copy paper | 75 gsm | 20 lb | — |
| Standard copy | 80 gsm | 21 lb | — |
| Letterhead | 90 gsm | 24 lb | — |
| Premium paper | 100 gsm | 27 lb | — |
| Light card | 120 gsm | 32 lb | 45 lb |
| Index card | 160 gsm | 43 lb | 59 lb |
| Light cardstock | 200 gsm | 53 lb | 74 lb |
| Business card | 300 gsm | 80 lb | 111 lb |
| Heavy cardstock | 350 gsm | 93 lb | 129 lb |
US paper weight is confusing because it depends on the “basis size” which differs between bond and cover stocks.